"It's a horrible situation that could have been prevented," said Sgt. Pam Perry, investigations manager for Animal Services.

Mia may have never seen the attack coming, according to reports from Animal Services and the Hillsborough Sheriff's Office.

Investigators said the dog spent most of Tuesday at Mia's home, at 11820 N Armenia Ave. Arthur is friends with the toddler's parents, Sean Kinsman and Jaime White.

Perry said the three adults were building a fort in the back yard. About 4:15 p.m., Mia turned her back to the dog and walked toward her mother. Perry said that's when Hunter attacked, clamping his jaws around the little girl's head.

Mia's father began beating the dog as Arthur choked Hunter to get him to loosen his grip, Perry said. Once they freed her, Mia's parents drove her to University Community Hospital in Carrollwood. She was transported to Tampa General Hospital, where she remained Wednesday in serious condition.

It was Hunter's first time visiting at Mia's home, Perry said.

She questioned why the adults allowed Hunter to roam freely in the back yard with the toddler and warned other dog owners to avoid the same mistake.

"It's not negligence," Perry said. "It's ignorance, and people need to be educated."

Arthur initially left the scene with his dog but returned when deputies called him. He surrendered Hunter to Animal Services. At first, he said Mia had thrown dirt in Hunter's face, then admitted that wasn't true.

"This is not a responsible individual," Perry said.

Authorities also cited Arthur for having an aggressive dog and expired dog tags. According to his Florida criminal record, Arthur has previous charges that include domestic violence, burglary, possession of drug paraphernalia and possession of marijuana.

Animal Services Cpl. Ken Vetzel said investigators planned to speak with Mia's parents Wednesday evening to get their account of the attack. Investigators also planned to talk with Arthur's former neighbors in Tampa and current neighbors in Hudson to see whether the dog had exhibited aggressive behavior before.

Times researcher John Martin and staff writer Rebecca Catalanello contributed to this story. Kevin Graham can be reached at kgraham@sptimes.com or (813) 226-3433.